ventis
There's one reason: if you login by Facebook before (and this fb account has the same gmail in account setting), then you logout, and login again by G account (which had been declared in the Fb account above), it will not redirect to your Google, it's mentioning about Fb account. It's the problem.
However, it's still the same people, although you tried to login by Fb or Google (as long as this fb account has this google declared inside)
